Food processing systems comprising a number of food items being substantially sequentially delivered to a number of workstations for processing are commonly known. One example is a trim table where pieces of meat are provided sequentially by a primary conveyor band. Workstations are located along the primary conveyor, where operators can trim a piece of meat for excessive fat, bones and low-quality meat, or cut the piece to obtain a piece of predetermined weight, size or shape. The allocation of meat pieces from the primary conveyor to the workstations are in advanced systems computer controlled, thus enabling automatic sorting of pieces to workstations for different types of processing, and keeping track of the pieces for traceability purposes. When a piece of meat is processed at a workstation it typically results in one or more of a main piece of meat, and bones, fat and cut off meat, so-called trim, possibly of different qualities. According to the possible use of the different categories, one or more secondary conveyor bands, baskets, bags, trolleys or other suitable means are arranged for transporting the meat and waste away. In a typical trim table an in-feed primary conveyor is transporting meat pieces to the workstations, and e.g. three secondary conveyors typically located underneath the in-feed conveyor and table are transporting a) main pieces, b) fat and trim and c) waste, e.g. bones, away. Systems of this type are for example known from the PCT patent applications published as WO 98/14370 A2, WO 01/91565 A1 and WO 03/077662 A1.
The fact that the processed meat pieces are transported away after processing requires a second trim table or set of workstations to be arranged at the out-feed secondary conveyor if more processing steps need to be made to each piece of food. In particular when only some pieces need further processing, and where this may even not be known before allocating it to a first workstation, it becomes impractical to establish this second stage of processing at a separate location. This is further strengthened by the fact that the operators best skilled for performing the second stage of processing of a particular piece of meat, e.g. a particularly difficult cut or trimming which the operator to which the piece was initially allocated is not suited to carry out, are probably working at the first trim table for doing this particular operation already.
Alternatively, a few adjacent workstations can work together to perform several processing tasks, e.g. as disclosed in WO 01/91565 A1, where the meat items are first provided by an overhead rail system to a number of de-boning stations, and each of these de-boning stations hands the de-boned items to two adjacent slicing stations. At the slicing stations, the de-boned and sliced items are transported away by a conveyor. This configuration does facilitate two processing steps to be performed (de-boning and slicing), but in a very inflexible way. In terms of flexibility, this configuration in practice equals one workstation receiving an item from one conveyor system, performs two processing steps and delivers the resulting items to a second conveyor system.
In both the above configurations the amount of different conveyors which transport the different categories of meat, trim and waste around the factory floor makes the planning and design of a processing system difficult and inflexible. This becomes particularly significant for smaller systems with only a few workstations, where still the same amount of conveyors, and thus space, is needed as for a huge system.
Another problem with the several conveyors transporting items away from the workstations is that they are typically arranged underneath the tables for space considerations and thereby considerably more difficult to clean than the primary conveyor, and frequent, thorough cleaning is a critical requirement in food processing systems because of food hygiene considerations.
An object of the present invention is therefore to improve the flexibility of transportation means as well as enabling more processing stages in food processing systems such as e.g. trim tables.